Chronic urticaria: Incidence of thyroiditis and response to medications

Abstract

Rationale Chronic urticaria (CU) continues to be a vexing problem for the allergist. This study reports the clinical characteristics of CU patients in a large allergy practice, and their response to medications. Methods Retrospective chart review identified patients whose primary diagnosis was “urticaria” between October 1998 and June 2003. Patients who met diagnostic criteria for CU were included in this sample. Treatment included high-dose H1 and H2 histamine receptor antagonists, and additional medications if this combination failed. Outcome of treatment was evaluated by assessing the degree of improvement as well as the time for resolution of symptoms. A subset of patients with thyroiditis was identified and characterized. Results All 197 patients were identified and characterized by age, race, associated angioedema, anti-thyroid antibodies, physical examination, provocative triggers, laboratory findings, medication usage, clinical outcome and long term resolution. Twenty-four patients were lost to follow-up. One hundred sixty-one (94%) had substantial improvement of symptoms while 10 (6%) had no change. Twenty-two patients (only one male) were positive for antibodies to either thryoglobulin or peroxidase, or both. Conclusions The outcomes of the chronic urticaria patients seen in this allergy practice suggest that a combination of H1 and H2 antihistamines may be quite efficacious and that patients overwhelmingly improve. Hashimoto's thyroiditis was seen in a significant subset of patients.